Indicating device



Oct. 19, 1948. s. ROSENBLUM INDICATING DEVICE Filed Sept. 4, 1943 IN V EN TOR. m WYOfi/Kr 509mm @W ATTORNEYS Patented Oct. 19, 1948 My invention relates to. a 1new andximproved indicatingdevice. it

- One of the objects of .my invention is to r'providea device which can be used for indicating writtenior .printed or pictorial messages in the darkfi Y zAnother object ofmy invention is to made a device of this type, whereby messages can bewrittenwand such messages can be readily re-' moved from the device. s.

Another object. of'my invention is to provide a-device of this kind, in which. the illumination is;provided either by a lamp or by a radioactive paint or byany suitable.phosphorescent. material; v

1:- Numerous additional objects of my invention will be stated in the annexed descriptionand drawings which illustrate preferred embodiments thereof..

.Fig.,.1:.is a diagrammatic vertical section of thefirst embodiment, in which I utilize a radioactive paint or other phosphorescent material.

:Fig. 2 is a-vertical diagrammatic section of the secondembodiment, in which I use a lamp as a source of illumination. r

Fig.1 shows a transparent glassbodyi which This glassbody.

hast-rent and rear planar faces. I: constitutes a non-compressible and light-permeable, carrier. Said glass body I may begrece" tangular- -orany other "shape. body I maybe made of any suitable, transparent. resin or other, transparent material. ,An adher-. entglayer 2 of a light-emitting or--fiuorescent compositionris applied to the rear facegof. the. carrierlgqsaid layer 2 may be applied .in the form of an adherent paint. The material of-said layer12 can include zinc sulfide intermixed with a radium. salt, so that said layer 2 will emit light continuously in the dark: duelto'the activation of the zinc sulfide or other suitable material. This layer 2 is either translucent or'transparent. Saidlayer 2 is covered by a reflecting layer 3 which is applied to the rear face of the layer 2. Said layer 3 may be an opaque reflecting white paint, or a mirror surfaceofany kind; -g 'l-he frontface of the carrier I is-provided with altablet layer' or writing layer 4 of a material which can be easily deformedunder pressure, and which will remainin its deformed shape under the applied pressure. Said layer 4 may be'a suitable wax, such as beeswax, a mixture of waxes, etc. Compositions ofthis type are well-known, so that they require no. further description. Such "com-positions are indentable at ordinary temperature of 70? by an unheated pencil or stylus. The iay'er'i is light-permeable and it is preferably translucent.

.1 g 'lheijcarriernl and its layers 2; 3and Mare permanently connected to each other, so as to form a sub-unit of the device.

Said carrier .or,

.vThe. reference numeral 5 indicates a thin and; flexible sheet of pyroxylin or other. suitable trans parent or'ltranslucent"material; Said thin sheet 5'; can be releasablyapplied to the .frontfaceof the layer 4. If desired, the sheet -5 may be kept The thin sheet-"5:

separate from'the layer 4. I is readily deformable under applied pressure; --'?Ihe reference numeral 5 indicates a light permeable' sheet of pyroxylin or other suitableflex-f ible and light permeable material. The sheet 6 is thicker than the sheet 5.

'In order to'use the'device of 'Fig. 1, the "thin andx'flexible sheet! is applied under little or no pressure to the front face of the tablet layeror writing layer Therewillibe'little or'no adherence between :sheetii: and layer i; The

sheet 5 is held against shifting, relative to layer 4;-- either by hand or in any manner. The flexible sheet 6 is applied to the front or exposed face of the sheet 5.

"The message is then written or drawn uponthel front face of the sheet 6, using a pencil or stylus or anyother tool which can exert the desiredwriting or I drawing pressure. J The writing or l, drawing pressurefis applied through the flexible" sheets fi a'nd 5 to the deformable material of the tablet layer 4, so that the tablet layer l is'indented along the line or lines or point or points which correspond to the words or pictures which" face of the layer 4 only at the points or lines where the writing or drawing pressure has been exerted, and where the sheet 5 and layer 4 have been indented. The sheet 5 is sufficiently thin and deformable so that it remains indented along the indented and thinned parts of the layer'4.,

The sheet 6 is sufilciently resilient so that it does not remain indented by'the writing or drawing pressure. Sheet 6 can be kept in place or re"- moved. 1

An observer who is located in-front of the sheet 5 will see the desired message, because the light which emanates from the layer 2 is reflected forwardly by the mirror layer 3, and there is enough contrast and diiferencein the light-permeabilit'y between the indented and thinned'pgntions ofjthevlayer Q .and'theunthinned and uhindentedflportions of said layer Afand between the, inden'ted .and .noni ndented portions or sheet 5,; iniiorder to make such message clearly visibleL After the message hasbeen exposed for the. desired-period, pressure can be applied over the; entire frontface; of the sheet 5 by rubbing said eetzaw tha e or. h b i t w h h s; straight edge. Said rubbing pressure will cause the layer 4 to assume the same thickness throughout, thus obliterating the message If desired, thestran'slucent sheet 5 "can?be peeled off the tablet layer 4 after the message has been obliterated, and said sheet 5 can then be reapplied I message. adherently connected to layer 4, said connection may be a releasable connection.

The device can thus be used;repeate dly fortransmitting written or pictorial messages in a' darkplace. i g

Without limiting the invention to the specific dimensions stated herein, the thickness of"'-the layer 4 may be about 0.011 inch, and the thickness of the thin pyroxylin' or Celluloid sheet Ermay be about:.0:3; inch..

Fig: 2'is the-"same as Fig; 1,:save that the layers: Ziand- 3 have been omitted. lnisuch case,-a lamp L, provides 'thetransmitted. lightifor reading the message, to an observerwho is located in. front of thex'sheeti.

. If' desired; the tablet layer 4-can be-readily remeredebys means; of: assuitablei solvent or by. mechanical action, and it can be repla'cedlby a fresh layer 4. i I have described preferred embodiments of my invention; but itj'isclearthat numerous. changesandomissionsand additions can be made; without departing from-itsscope.

For example, the; layer 4 maybe transparent onsubstantially; transparent, :instead of being: translucent. Likewise; the-layers 5 and;6maybelight-permeable to any desiredextent.

Likewise, in the embodiment of Fig.2, a phos-l' phorescentlayer 2, without a; radio-active compound therein, can beprovided. Said phospho-- rescent layer 2 can be activated when. desired lo fpermeable layer of light-emitting material by ra-ys emitted by asuita-ble lamp; Hence,-after; therdamp L has: been: extinguished, the layer 2: 40

will emitlightfor a substantial period of time...

. Irclaim:

1; Anindicating device comprising anon-comapressible and light-permeablecarrier; light-emittingqmaterial located-upon therear-face: ofj said; carrier in--order to transmit, light through said' carrier; tablet.material located' .onthe'front face of said' carrier, said tablet materiatbeing light permeable so that the lightwhich;isemitted.1by; said light-emitting material willbe; transmitted: through said .tabletmaterial, saidtablet. mate-rial; being sufiiciently deformable under pressure to changeits permeability to-light solely under apt-5 plied: pressure, to;-provide the necessary contrast. for reading: the, markings which, are made in: said; tablet: :material by applied. pressure; said tablet material being adherent, a writing, tablet .applied totthe. front face-of said tablet material, said writing tablet being light-permeable and "beingdeformable under pressure, so. that pressure whicl'ris-appliedtothe front face ofsaid writing, tablet is transmitted through, said .writingtablet to deforrnthe tablet material at 'thepointfof applied pressure.

2.}An indicating-device comprising iaflfnon compressibleand light-permeable carrier; a iayer of'ili'ght-permeable. and light-emitting material located upon the rear face of said carrier in order to transmit light through said carrier, tablet material'located on the front face-of said carrier,

said tablet material being-light-permeable sothat the light which is emitted by :said light-emitting material will be transmitted through said tabletmaterial, said tablet material-"being suIficientl-y 4 deformable under pressure to change its permeability to light solely under applied pressure, to provide :the ne'cessary contrast for-reading the markings which are madei-n said tabletmaterial by applied pressure, the rear face of said layer of "light-emitting material having an opaque reflecting rnember applied thereto. 7 3. An indicating device comprising a non-compressible and light-permeable carrier, a lightlocated upon the rear face of said carrier in order to transmit light through said carrier, tablet material located on the front face of said carrier, saidtabletmaterial being light-permeable so that the light which is emitted by said light-emitting materialrwillrbe transmitted; through said tablet material, said tablet material being." sufficiently" deform-able under pressure to change. its; permeabilityto light solely under. applied. pressure;.tor provide the necessary contrast for readingrthe markings which are made in said tablet material" by applied pressure, said: tablet materialbeing adherent, a writing tablet applied to:.the.= front: face of said tablet materiaL-said writingtablet" being light-permeable and being deformablmun der pressure, so that pressure which is applied? to the front face of said writing'tablet is'transmitted through said Writing tablet to deform the.= tablet material atthe point of. applied'pressure;. the rear face of said layer of light-emitting mate:- rial having'an opaque reflecting member-applied thereto. I

4'. An indicating device comprising: anon-com pressible and light-permeable carrier, a layer of. writing material which is adherentlyconnectedto and which abutsaface of said carrier, saidlayer: ofwriting material being indentable under applied pressure at F., a writing tablet adherently connectedto and abutting the free face of said layer of writing material, said writing tablet being light-permeable and being deformableunderpressure, so that writingpressure which is applied to saidj writing tablet will betransmitted' through said'writing tablet to deform" the-respec-- tive part ofthe layer of'writing materiallsaid layer of writing material being sufiiciently de formable under said applied pressure to make-a marking thereon under such pressure, whichis visible under transmitted light'through said 'car-- rier and through said layer and through said writing tablet; SOLOMON ROSENBLUM.

REFERENCES CITED UNITED; STATES PATENTS;

Number Name Date 886,782 Easterbrooks May" 5, 1908 1,351,935" Willis Sept. 7,' 1920 1,373,783 Willis; Apr; 5', 1921 1,374,875" Bethke"; Apr: 12, 1921' 1,375,816" Bethke Apr. 26,1921. 1,385,798 Sirotet al. July 26', 19.21 1,816,220 I-Iotchner July 28,' 1931' 2,135,538 Sherman et al. Novy8, 1938' 2,334,766 Herman Nov. 23; 1943- 23723209 Kohler Mar; 27, 1945 1 FOREIGN PATENTS Number Country Date 404,801 Great Britain- Jan. 25;1934 

